Nalco (NYSE: NLC), providing essential expertise for water, energy and air, has again been named among the top sustainability companies in world. The Company was named to the Dow Jones Sustainability Index (DJSI) World Index for a fourth consecutive year and to the North America Index for the second straight time. The DJSI World Index captures the top 10 percent of the world's 2,500 largest companies based on economic, environmental and social criteria. The North America Index captures the top 20 percent of the 600 largest companies in the United States and Canada.

"Nalco employees often tell me that their greatest satisfaction each day at work comes from the difference we are making for our customers and our world," said J. Erik Fyrwald, Nalco Chairman and Chief Executive Officer. "It is especially rewarding to have those efforts recognized by again being named to the Dow Jones Sustainability Index. Our sustainability solutions deliver an environmental return on investment, or eROI, for our customers by both shrinking their environmental footprint and their total cost of operations."

Details of the many sustainability solutions Nalco provides, and the company's own environmental, economic and social performance, can be found in its 2010 Sustainability Report, available at www.nalco.com/sustainability.

Launched in 1999, the annual review of the Sustainability Indexes is based on a thorough analysis of corporate economic, environmental and social performance, assessing issues such as corporate governance, risk management, branding, climate change mitigation, supply chain standards and labor practices.

There are 342 companies listed in the 2011/12 World Index and 143 companies listed in the North America Index. More information on the DJSI Indexes is available at http://www.sustainability-index.com.